290 BOTANICAL GAZETTE [may 



Filix-mas cristatum archegonia are apparently absent, in Pteris cretica 

 they never fully developed; although all prothallia bear more or 

 less numerous antheridia. 



Sadebeck in the following year reported apogamy in Todea 

 africana (in Schenk's Handbuch der Botanik 1:233. 1879). And 

 later apogamy was found in Osmunda regalis and Ceratopteris 

 (Leitgeb 38) ; Todea rivularis, T. pellucida (Stance 63) ; Doodya 

 caudata (Stance 63, Heim 29); Trichomanes alatum (Bower 6); 



Selaginella rupestris (Lyon 43) ; Trichomanes Krausii, Pellaea 



fla 



N 



Notochlaena Eckloniana, N 



Marantae, Gymnogramme farinif, 



some others. 



Lanc's study (36) of the apogamous development of the sporo- 

 phytes on prothallia of several forms of Polypodiaceae is the most 

 detailed contribution on apogamy in pteridophytes. The paper 

 presents a discussion of the phenomenon in relation to alternation of 

 generations, and adds detailed descriptions of the results of cultivating 

 prothallia grown from spores, for a period of two years and a half in 

 the following fourteen forms: Aspidium aculeatum Sw. var, miilti- 

 fidum WoU, A. angulare Willd. var. joliosum muUifidum, var. aaili- 

 joUum muUifidum (no apogamy seen), A. jrondosum Lowe; Athyrium 

 nipponicum Mett., var. cristatum, A. Filix-joemina Bcrnh. var. 

 percnstatum Cousins, var. cruciato-cristatum, var. coronatum Lowe; 

 Nephrodium dilatatum Desv. var. cristatum gracile, N. Oreopteris var. 

 coronans Barnes; Poly podium vulgare L. var. grandiceps Fox; 

 Scolopendrium vulgare Sm. ^'ar. r amnios is simiim Woll, var. marginale. 



According to his account, the apogamous growth resulted from 

 artificial cuhures, watered entirely from below and exposed to direct 

 sunUght, important departures from the normal conditions surround- 

 ing fern prothallia. The asexual sporophytic outgrowth from the 

 prothallia present some minor differences in different individuals, 

 but, taken as a whole, they arose in the following ways : as leaves, 

 roots, and ramenta directly on the prothallia or on a cyUndrical 

 process from the prothallium; as a continuation of the process as a 

 leaf; as sporangia on the process from the prothalhum; as tracheids 

 m the prothallia or in the middle lobe and cylindrical process. 



It seems hard to draw from these experiments any more precise 



